Universal Factory Sound System Interface

Item #: 127OEM2

23 Reviews

This item is no longer available.

Original Price: $29.99

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The PAC OEM-2 is a universal sound system interface and controller which can be used for a variety of purposes:

  • connecting an aftermarket radio to a common-ground speaker system;
  • converting a factory radio's speaker-level outputs to preamp-level signal that can be connected to aftermarket amplifiers;
  • adding aftermarket amplifiers to factory premium systems (Bose, JBL, etc.);
  • connecting an aftermarket radio to a factory amplifier.

The unit has independent level controls for each of its 4 channels, so you can adjust output for any amplifier. It also features remote turn-on outputs for amps and power antennas.

Note: Most vehicles will require additional installation parts — please identify your vehicle if you haven’t done so. You can also call an Advisor for more information.

    • 4-channel input and output wiring
    • power, switched power, illumination, remote turn-on, and ground connections
    • input power range: 2 to 60 watts RMS
    • frequency response: 20-20,000 Hz
    • warranty: 1 year
    • Our 60-day money-back guarantee

    PAC OEM-2 Reviews

    Average Customer Review:

    23 reviews
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    PAC OEM-2

    Written By steve, boston on Wednesday, January 20, 2010

    Crutchfield Customer Review (What's this?)

    Worked like a charm..

    1999 Mercedes

    Written By Rob, New York, NY on Sunday, November 08, 2009

    Crutchfield Customer Review (What's this?)

    Used this interface to install a new head unit in my 1999 Mercedes c280 with Bose system.
    Attached all the wires to the supplied harnesses following the documentation supplied by
    Crutchfield, plugged it in, and not one problem. Didn't have to make any adjustments or

    Saab 9000 stereo

    Written By Blue, Smithfield, VA on Tuesday, August 25, 2009

    Crutchfield Customer Review (What's this?)

    Two years ago I installed a Blaupunkt Key West MP36 in my daughter's Saab 9000 CSE (OEM had failed), but only connected it to 4 speakers and bypassed the amplifier due to lack of technical expertise. Finally had time to finish project and ordered PAC OEM-2 based on advice from Crutchfield representative. Technical support was superb and patient with me through completion. Now OEM sub-woofers and OEM amplifier work as designed and I must say the entire system sounds great especially considering the small amount of money I spent for the PAC OEM-2. A great choice!

    PAC OEM-2

    Written By Marcus, Santa Clarita, California on Tuesday, May 05, 2009

    Crutchfield Customer Review (What's this?)

    My Mercedes-Benz CLK has a factory Bose system. The Bose system in my car has balanced differential amp input connections. The output from most aftermarket head units is an unbalanced signal. A person "could" plug unbalanced preamp outputs into Bose system amps, but the result will be inadequate signal amplitude. The PAC OEM-2 corrects the signal.

    If this sounds confusing to anyone, I'll make it as simple as possible - if you're using an aftermarket head unit with a Bose system, it will sound better if this box is used.

    does its job

    Written By bob, ft wayne IN on Tuesday, April 21, 2009

    Crutchfield Customer Review (What's this?)

    Chrutchfield didn't really explain how I was suppose to use this. One call though and now I understand

    is not required for your rf amplified 09 titan

    Written By bam, florida on Monday, March 09, 2009

    Crutchfield Customer Review (What's this?)

    you can play it safe and purchase this but I hooked my aftermarket player to my rf amplified system and it sounds perfect without it, going on 2 weeks and no problems.

    Did not work with '89 Audi 100

    Written By Art, Easton, PA on Monday, February 09, 2009

    Crutchfield Customer Review (What's this?)

    This product is not a working solution for '89 Audi where each speaker has it's own built-in amp. Crutchfield should consider another solution.

    Didn't Use It

    Written By propflux01, Central Arkansas on Saturday, January 17, 2009

    Crutchfield Customer Review (What's this?)

    Product was shipped to me along with a Pioneer FH_P8000BT Tuner and all the other stuff to install it into my 2006 Hyundai Sonata with factory Sub and amp. This was to be used in conjunction with a Ford-style adaptor. I took one look at this and thought "Geez, how many more wires I gotta deal with, and where is this thing gonna fit along with the HD tuner, wires and other stuffI am cramming into my dash?" After a little research, and trial and error, I found that for the factory Sub system, my needs would be better served buying a different harness. WAY much simpler, has added wires for proper operation of the steering wheel remote, which the harness Crutchfield sent didn't.

    Make sure you need it 2 (...or want it?)

    Written By ALBERTO, San Juan, Puerto Rico on Saturday, January 10, 2009

    Crutchfield Customer Review (What's this?)

    CASE STUDY: 2000 LR Discovery w/Harmon Kardon high end factory system. Factory head unit made by Alpine burned out so a replacement was in order. I hooked up a Sony CDX-GT820IPod to one of these OEM-2's and it worked pretty decent. After a week of driving I was upset with the overall fidelity. If you're like me, an old song is like and old friend and we know it's every nuance. That combined with the fact that I know what those Harmon/Kardon speakers could do left a sour taste in my mouth.

    Here's what was happening...A new premium head unit (in my case Sony) was putting out a clean line signal into the OEM-2 only to have it "knocked
    down" to safe level for the car installed Harmon/Kardon amp to able to
    handle it. The amp in turn would take this modified signal and kick it up again. The signal degradation was unsatisfactory for me. Word of caution, I did verify that the speakers did not have chassis ground and the LF & RF low freq were put in parallel with the LF & RF high freq leads. the MID & TWT had filter caps and the head unit was put at a 125Hz LPF mode. A small mono-block with a ten sub to top it off and now I'm smiling baby!

    I can see this item being very usefull in some weird vehicle applications but in my opinion, your overall sound quality will be compromised a bit.

    no more hissing

    Written By Brian, Warrensburg, MO on Tuesday, November 04, 2008

    Crutchfield Customer Review (What's this?)

    This adapter was what I needed to finally get rid of the annoying hissing sound my speakers were making after I installed an aftermarket head unit into my 2003 pontiac vibe with the factory amplifer.

    Works Perfectly w/ Hyundai Monsoon System

    Written By Robert, Arlington, VA on Monday, October 20, 2008

    Crutchfield Customer Review (What's this?)

    This unit made it easy to install a JVC HD receiver in my Hyundai Santa Fe with the Monsoon sound system. A perfect match between the receiver and the factory amplifier. The unit offers 4 possible set ups in its instructions. I was not sure which one applied to my installation but a call to Crutchfield support quickly answered my question.

    Make sure you need it

    Written By 3dollabill, Lee, NH on Friday, October 03, 2008

    Looks like it would be a solid product. However i didnt actually need it even though it said it was a necessary acessory. For all you 1995 bmw 525i owners the bmw wire harness adapter will do fine.

    Didn't even need this.

    Written By Chad, Ankeny, IA on Wednesday, May 28, 2008

    Crutchfield Customer Review (What's this?)

    Make sure you
    actually NEED to
    'Prevent Extensive
    Rewiring' before you
    order this. The
    harness adapter from
    Crutchfield was
    adequate to install
    my new head unit.

    00 GTP with bose

    Written By Jesse, Baldwin,WI on Thursday, April 10, 2008

    Crutchfield Customer Review (What's this?)

    great product works great with factory bose system thanks crutchfield

    PAC OEM-2

    Written By Jim, Vancouver, BC on Monday, October 22, 2007

    Crutchfield Customer Review (What's this?)

    This product worked well to install an Alpine receiver into my Porsche Boxster. The instructions were clear and complete. The installation would have been easier if a wiring harness were available to connect the interface audio output to the yellow Porsche connector that normally plugs into the standard Becker radio and leads to the amplifier. As it was, I had to cut off the connector and attach the audio output wires directly to the leads. This part was rather difficult as the leads do not extend far out of the dash. Aside from the installation difficulty that is likely specific to Porsches, the product is excellent.

    If only it worked the first time

    Written By michael, NY on Friday, September 21, 2007

    Mine came defective. There was a constant buzz coming from one speaker With the help of tech support we determined it was the PAC OEM causing the problem.

    Crutchfield is sending me another one...but the thought of having to do all the wire connections again is really a turn off.

    Works really well in my 96' BMW 328is

    Written By Amar, West Orange, NJ on Tuesday, September 18, 2007

    Crutchfield Customer Review (What's this?)

    I never would have known that I needed this adapter if it wasn't for Crutchfield. It works nicely. Only issue is that the size of the box really made it a pain to fit everything in the dash behind the DIN stereo. Get it or you might blow your amp. Russ in tech support: you the man!!!

    Didn't need this

    Written By Andy, Atlanta, GA on Saturday, August 04, 2007

    I ordered a Pioneer head unit and I have a 2005 Acura RSX. I was replacing the factory head unit, and while recommended to 'prevent extensive rewiring' it was completely unnecessary. I gave the 3 stars b/c there may be some ppl who need it, but when I got my unit all I had to do was assemble the wiring harness and that was it; in fact I'm kind of clueless what this item would have done to help things out.

    Good Adapter, but incorrect for Grand Prix with Bose Factory Systems

    Written By Anonymous, Reno, NV on Thursday, May 17, 2007

    Crutchfield Customer Review (What's this?)

    This adapter is a good adapter, and once it was adapted for my system by my buddy who is a pro installer, and an additional adapter that we made was put in in addition to an adapter we had to fabricate ourselves it did finally work for it's intended purpose. However if you have a Grand Prix with a Bose Factory System without onstar you will still want the PAC GM21B adapter, and the OS-1 Bose Adapter. While it is more money it will be worth your time to pay the extra. If you do however to go this route to be able to translate your signal this is a good adapter you will however have to find a way to make an adapter to go from the Remote on of your head unit to the pink wire in the extra plug so that you can use your Bose amp will kick on so that you will have volume.

    Easy Peezy

    Written By Luke, Clearwater, FL on Wednesday, March 28, 2007

    Crutchfield Customer Review (What's this?)

    I was told by other various places on the web that my 93 Lexus ES300 needed a complete new system if replacing the factory premium head unit. All lies. Crutchfield wins again with another quality product.

    Sounds better than stock and works like a charm.

    Above and beyond!

    Written By Mario, Germantown,MD on Monday, September 25, 2006

    Crutchfield Customer Review (What's this?)

    Unfortunately this item did not work with my set up. I rated it a 5 b/c it's not it's fault my premium sound system was not compatible w/ it. I have an E30 BMW to which i was installing an Alpine CDA-7984. As I stated before it did not work but this is not a review about the product but the service.

    Dean and Tom were the two techs that helped me figure things out. Once we realized this PAC adapter was not going to work for me they still helped me in getting my older receiver intalled. I was most pleased and impressed by their knowledge and the curtious service they provided.

    Crutchfield is bar none my favoriate supplier of electronic goods. They go above and beyond to ensure customer satisfaction and really take the fear out of shopping online.

    Thank you Crutchfield and in particular, Dean and Tom. You are an asset to this company and I look forward to doing business with you again.


    Written By Joe, Hershey, PA on Tuesday, September 05, 2006

    Crutchfield Customer Review (What's this?)

    This thing does everything that it says it will do. And it does it well. It fits so many different applications. And beyond all that, they include gain pots for each channel so you can adjust your levels all around. Using one of these may not be the ideal install for discriminating audiophiles, but for the average car audio customer, it's perfect.

    interface class 101

    Written By Kevin, RICHMOND VA. on Wednesday, April 19, 2006

    Crutchfield Customer Review (What's this?)


    Hands-on research

    What's in the box?

    Download owner's manual

    • 1 Universal 4-channel Line Output Converter/Factory Amp Interface adapter

    Product Research


    Applications: The OEM-2 is a universal sound system interface and controller, which can be used to: 

    • connect an aftermarket radio to a common ground speaker system
    • convert speaker level output to preamp output; this allows you to feed aftermarket amplifiers signals from factory or aftermarket radios without preamp outputs
    • add aftermarket amplifiers to factory premium systems (Bose, JBL, etc)
    • connect an aftermarket radio to a factory amplifier
    Remote Turn-on Connections: This unit includes remote turn-on outputs for amplifiers or a power antennas. It will provide 2A at 12V when 5V or more is applied to the input side; the 5V trigger threshold is especially useful when this item is used with a Ford factory radio that supplies a low voltage trigger. There will be a 2 second delay of the turn-on lead to prevent turn on pops.

    Independent Level Controls: This adapter has 4 independently controlled potentiometer outputs to adjust the signal level of each channel. These potentiometers are sealed to prevent circuit-induced distortion and signal drift.

    Inputs/Outputs: On the input side of the adapter, there are 6" long wires for the signal input, constant power, switched power and remote turn-on connections. On the output side of the adapter, there are two sets of RCA preamp outputs on 9" pigtails, and there are 6" long wires for the signal output, constant power, switched power and remote turn-on connections. Refer to the instructions for specific information on wiring configuration for your particular application.

    Input power range: 2 to 60 watts

    Linear Frequency Response: 20 to 20 kHz +/- 0.5 dB


    Our Product Research Team

    At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.